Glow plug light doesn't illuminate. Car doesn't turn over.

rsbidinger · 2019-04-05

So strange. My 1980 Rabbit Diesel has been running everyday with no issues. Tried starting this afternoon and I noticed the glow plug light didn't illuminate. Still waited about 20 seconds before turning the key. Car starts (starter whirls like normal, very quickly), but can't get the engine to turn over. Any ideas? Not getting much luck in my Bentley manual.

briano1234

· #2 · Apr 5, 2019

Probably the Relay.... or the LED, Try taking the relay out and cleaning the contacts as that is what powers the glowplugs.

Check the fuse @ f11 first tho, as that is what starts the biasing of the lamp. then check the fusible link on the battery.

Throw the Bentley out for wiring on the Westy, and use Chris's pages http://chris.chemidl.in/vw-wiring-diagram-pdf-1982-1983-1984/

See less See more

Reply

Save

Like

rsbidinger

Discussion Starter · #3 · Apr 5, 2019

3

Thank you, Brian. Checked F11 on the fusebox and it looks good. Replaced it just in case. Still no change. I'll try the relay next.

What about the glow plug fuse? I found this one from Nov '84 in my glovebox!

Not sure where it goes though. I know it says on the firewall but I can't find it. Regardless, should I even bother?

Is this where it is?

Thanks for your help.

See less See more

Reply

Save

Like

rsbidinger

Discussion Starter · #4 · Apr 5, 2019

2

Ok, confirmed that's the fuse box but it looks like it's been bypassed the entire time (all wires on one side of the terminal, as shown). Now I'm having trouble finding the relay. THere's one that hangs loosely that I think is the right one. Any way to confirm? The contacts look right. Here's what it looks like:

Bumper Automotive exterior Auto part Automotive tire Vehicle

Contacts look clean. Could you remind me how to test it? Thank you.

See less See more

Reply

Save

Like

briano1234

· #5 · Apr 5, 2019

on 4crawlers site he has the part numbers for the relays, as in there are 2 types the Wait-for-ever, and seven second ones.

https://www.4crawler.com/Diesel/GlowPlug.shtml

Also vince waldon has some troubleshooting info as well.
https://vincewaldon.com/index.php?option=com_content&task=view&id=41&Itemid=28

Reply

Save

Like

ORCoaster

· #6 · Apr 6, 2019

rsbidinger, I was going to suggest the fuse on the firewall but it seems you found that the PO has over ridden that possibility. I would insert that fuse as it should be, you have it, make it right and move that wire over to the other post and put the fuse in line.

I wouldn't be surprised if the link in the big red wire coming from the battery isn't toasted. I have had to replace that on both my 81's and I did it with a regular fuse like you use for a stereo. Big amps and I put it in a water resistant case. Auto parts place has em. Might as well upgrade when you can. You could do that for the one on the firewall too if you'd like to have a fuse type that you can buy most places and not rely on that tin strip you have. Very classic on the 3 by 5 card stock by the way.

I would also be checking the individual glow plugs themselves. You can generally get the engine to fire up on one GP. It might struggle but it does get going. It might just be that all four GP's have finally bit the biscuit.

Keep us posted.

See less See more

Reply

Save

Like

briano1234

· #7 · Apr 6, 2019

Just a thought, you said the starter spins, but the engine doesn't turn over?

Does the engine turn over but not catch?
Cause that means something different to me than what you typed.

If you take the number 3 and number 4 glow plug out do they get red hot in 7 to 20 seconds? If not then you have bad glow plugs, as the cars will usually start on 1 good one, but when that one goes you will be hard pressed to get it to start.

So you may want to verify that your GP's are good.

The seven second ones usually only lasted about a year to a year and a half on me. So I always carried a spare in the glove box as well as the 2 wrenches that too to remove it.

Reply

Save

Like

rsbidinger

Discussion Starter · #8 · Apr 6, 2019

Excellent. Thank you, Brain. I'll take a look at this.

briano1234 said:
on 4crawlers site he has the part numbers for the relays, as in there are 2 types the Wait-for-ever, and seven second ones.

https://www.4crawler.com/Diesel/GlowPlug.shtml

Also vince waldon has some troubleshooting info as well.
https://vincewaldon.com/index.php?option=com_content&task=view&id=41&Itemid=28

Reply

Save

Like

rsbidinger

Discussion Starter · #9 · Apr 6, 2019

Yes, I completely agree. I'll do that.

ORCoaster said:
rsbidinger, I was going to suggest the fuse on the firewall but it seems you found that the PO has over ridden that possibility. I would insert that fuse as it should be, you have it, make it right and move that wire over to the other post and put the fuse in line.

Yeah, Brian suggested taking a look at the link too. I'll do that also. Converting it to a fuse type seems like an easier solution to me too. I've done that before installing a dual battery in my '04 Toyota Tacoma. Thanks for the suggestion! I'll let you know what I find out.

ORCoaster said:
I wouldn't be surprised if the link in the big red wire coming from the battery isn't toasted. I have had to replace that on both my 81's and I did it with a regular fuse like you use for a stereo. Big amps and I put it in a water resistant case. Auto parts place has em. Might as well upgrade when you can. You could do that for the one on the firewall too if you'd like to have a fuse type that you can buy most places and not rely on that tin strip you have. Very classic on the 3 by 5 card stock by the way.

Yeah, I suppose that's a possibility. I'll test them out. Did this a while back troubleshooting the IP.

ORCoaster said:
I would also be checking the individual glow plugs themselves. You can generally get the engine to fire up on one GP. It might struggle but it does get going. It might just be that all four GP's have finally bit the biscuit.

Will do. Thanks for your help!!

ORCoaster said:
Keep us posted.

Reply

Save

Like

rsbidinger

Discussion Starter · #10 · Apr 6, 2019

Yes. Sorry for not clarifying. It spins and turns over just fine, but doesn't catch.

Maybe I should test the glow plugs then before the relay.

briano1234 said:
Just a thought, you said the starter spins, but the engine doesn't turn over?

Does the engine turn over but not catch?
Cause that means something different to me than what you typed.

If you take the number 3 and number 4 glow plug out do they get red hot in 7 to 20 seconds? If not then you have bad glow plugs, as the cars will usually start on 1 good one, but when that one goes you will be hard pressed to get it to start.

So you may want to verify that your GP's are good.

The seven second ones usually only lasted about a year to a year and a half on me. So I always carried a spare in the glove box as well as the 2 wrenches that too to remove it.

Reply

Save

Like

briano1234

· #11 · Apr 6, 2019

3

View attachment 38355

Contacts look clean. Could you remind me how to test it? Thank you.

The contacts that I am talking about are inside the black cover, you have to use a couple of small straight blades to pry the cover off, then inside are the set of contacts that I mean.

Here is an a/c relay that I took apart.

It was a spare that evidently got water logged.

See less See more

Reply

Save

Like

rsbidinger

Discussion Starter · #12 · Apr 7, 2019

Thanks Brian. Opened it up and it looked brand new, so I started testing the glow plugs. Sure enough, they were all bad. Replaced them all and the dash light came back on. Engine caught immediately. Woohoo!

Interesting even with—what I assume was only one glow plug being used to get the engine running before it failed altogether, there was no indication of any trouble trying to get it started. But now I can feel an obvious increase in performance I didn’t have since replacing the IP.

Thank you all for your help!

Reply

Save

Like

briano1234

· #13 · Apr 7, 2019 (Edited)

Your Welcome, when I converted my 81 over from the wait-forever to 7 second plugs I had a ride awakening...my car wouldn't start.
The diesel will start with one good glow plug, but when that goes even here in Georgia in the summer NADA bing Notta bang called a tow the first time. What I have come to realize is that they usually go bad one or two at a time, and the car will start on 3,2,1 but not on none.

When I tested the 3 and 4th plug and they didn't get warm, I replaced them and the car started better than it did, when I replaced the other two 1, and 2 it really rather started quickly and ran better cold.. Go figure... So I started to carry a spare couple of plugs and the wrenches to swap them (ok sockets 1/4 drive deep well and extension) in my glove box and when the car wouldn't start, that number 4 was the first one I changed..

What was really funny was the wait-for-ever ones I had originally lasted about 135K and a few years, and when I tested those, they were still good...I think it is the higher amperage that the 7 second ones use that makes them burn out 1-1.5 years....

Glad you got it sorted.

See less See more

Reply

Save

Like

rsbidinger

Discussion Starter · #14 · Apr 9, 2019

Great to know. I'll start carrying an extra plug and wrench with me at all times!

Boy, #2 & 3 are hard to reach. Barely got the plug and little bolt that holds the electrical bar off with my fingertips.

briano1234 said:
Your Welcome, when I converted my 81 over from the wait-forever to 7 second plugs I had a ride awakening...my car wouldn't start.
The diesel will start with one good glow plug, but when that goes even here in Georgia in the summer NADA bing Notta bang called a tow the first time. What I have come to realize is that they usually go bad one or two at a time, and the car will start on 3,2,1 but not on none.

When I tested the 3 and 4th plug and they didn't get warm, I replaced them and the car started better than it did, when I replaced the other two 1, and 2 it really rather started quickly and ran better cold.. Go figure... So I started to carry a spare couple of plugs and the wrenches to swap them (ok sockets 1/4 drive deep well and extension) in my glove box and when the car wouldn't start, that number 4 was the first one I changed..

Funny. Reminds me of after-market headlight bulbs. Don't last near as long as stock!

briano1234 said:
What was really funny was the wait-for-ever ones I had originally lasted about 135K and a few years, and when I tested those, they were still good...I think it is the higher amperage that the 7 second ones use that makes them burn out 1-1.5 years....

Glad you got it sorted.

Reply

Save

Like

Top Contributors this Month